Merrychef High-Speed Oven Error Code E105: Frequency Supply
E105 means the mains supply frequency is 2 percent off nominal, or something is interfering with it, such as an internal microwave leak. The manual notes it is often an unstable building supply, for example generators. Check the supply and error log, and check for microwave leaks.
Medium: a warning about supply quality that can point to a leak.
- Code
- E105: FREQUENCY SUPPLY
- Maker
- Merrychef
- Equipment
- High-speed ovens
- Applies to
- All Merrychef eikon speed ovens (e2s, e3, e4, e4s, e5, e6)
What does Merrychef E105: FREQUENCY SUPPLY mean?
The SRB measures the frequency of the incoming mains. If it is more than 2 percent from nominal, the display shows E105: FREQUENCY SUPPLY as a warning. Two situations are named. The first is a supply that is not stable, which the manual says is common with generators and weak building supplies. The second is electrical interference reaching the board, such as a microwave leak inside the oven. The manual's actions follow. Look at the supply and the error log, check for microwave leaks with a leak detector, and check for a damaged cavity thermocouple. The percentage matters: 2 percent of 60 Hz is only about 1.2 Hz, so a generator running slightly fast or slow, or a heavily loaded one, can trip it.
Affected models and control systems
Merrychef eikon e2s with the QTS touch screen and SRB relay board controller, written from the e2s service manual's warning list.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- E105 FREQUENCY SUPPLY warning on the screen
- Warning appears when a generator is running
- Erratic behavior of the oven's display or cooking
Possible causes
Listed in Merrychef's documentation
- Unstable supply (generators)
- Microwave leak interference
Other likely causes — what usually sits behind E105: FREQUENCY SUPPLY on this control. A technician confirms which one it is before any part is replaced.
- Generator speed hunting up and down under load
- A damaged cavity thermocouple lead picking up interference
- Door seal or door damage letting microwave energy escape
Safe checks before calling for service
- Find out whether the oven is on a generator or an unstable supply.
- Check whether the warning appears only when other large equipment starts.
- Look at the door seal for visible damage, without touching the cabinet.
- Write down when the warning happens and what else was running.
How a technician diagnoses E105: FREQUENCY SUPPLY
- Read the log and see when E105 occurred.
- Measure supply frequency and voltage with a meter under normal load.
- Check the cavity thermocouple and its wiring for damage.
- Test for microwave leakage with a leak detector around the door and seals.
- Correct the supply or repair the leak, then watch the log.
- Microwave leakage testing needs a calibrated detector and knowledge of safe limits.
- Measuring supply frequency means working on live equipment.
How E105: FREQUENCY SUPPLY differs from similar codes
E105 is the supply frequency warning, while E088 is the supply voltage error that stops the oven.
Technical reference
- Maker documentation
- Merrychef owner support
- Edition
- Feb 2021/v1; 50Hz & 60Hz, English
- Models / control
- All Merrychef eikon speed ovens (e2s, e3, e4, e4s, e5, e6)
- Section
- Section 5 Service information, Error codes & fault finding tips (Warning Error Codes)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Merrychef high-speed oven error codes
Is the oven damaged by a generator?
E105 warns that the supply is unstable. A steady, correctly rated supply is the fix.
Could a microwave leak cause E105?
Yes. The manual lists interference such as an internal microwave leak as a possible cause.
Is the limit 2 Hz?
No. The manual gives 2 percent from nominal.
Need help with Merrychef E105: FREQUENCY SUPPLY?
A technician confirms the cause on site and gives you the price in writing before any work starts.